-2 1/5 - 1 3/10 help!!

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Mike wants to make meatloaf. his recipe uses a total of 8 pounds of meat. if he uses a 3 to 1 ratio of beef to pork, how much pork will he use? enter your answer as a mixed number in simplest terms.

Which of the following parabolas opens up?